JP2005083402A - Connection structure and bonding member for cross linking polyethylene pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connection structure for cross linking polyethylene pipes capable of effectively utilizing resources and fusing cross linking polyethylene pipes securely and accurately while facilitating construction at site. <P>SOLUTION: A polyethylene bonding member 200 is mounted on a connection end side of the first cross linking polyethylene pipe 100 with the second cross linking polyethylene pipe 300. The second cross linking polyethylene pipe 300 is provided with a recessed region 302 in which a heating body 400 having a spiral shape is arranged. The bonding member 200 is composed of a cylindrical part 201 and a flange part 202. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a connection structure of a crosslinked polyethylene pipe having a simple structure.

  Conventionally, polyethylene pipes (piping, joints) have generally been used as water distribution pipes. However, for example, in floor heating facilities and the like, since warm water close to 90 degrees is used, a polyethylene pipe cannot be used from the viewpoint of heat aging resistance. Therefore, in recent years, cross-linked polyethylene pipes (piping, joints) having better heat aging resistance than polyethylene pipes have been widely used.

  Here, the term “crosslinked polyethylene” refers to an ultra-high molecular weight polyethylene having a three-dimensional network structure obtained by bonding the points of chain-structured polyethylene molecules as thermoplastics. Therefore, at the time when the crosslinking reaction is completed, the polyethylene has a three-dimensional network structure like a thermosetting resin. As a result, the cross-linked polyethylene has improved ESC (environmental stress cracking), creep performance, chemical resistance, and heat aging resistance compared to polyethylene.

  When cross-linked polyethylene pipes having such characteristics are piped on site, the cross-linked polyethylene pipes cannot be directly connected to each other. Therefore, polyethylene is interposed between the cross-linked polyethylene pipes and fused by electrothermal heating. It is generally done. In addition, since polyethylene is required for fusion between crosslinked polyethylene pipes, a two-layer extruded pipe using crosslinked polyethylene for the inner layer and polyethylene for the outer layer is widely used in the market.

  However, in the case of the cross-linked polyethylene pipe having the above two-layer structure, a polyethylene layer provided outside the mutual fusion region is not necessary, so it cannot be said that it is appropriate from the viewpoint of effective use of resources. Further, in floor heating facilities and the like, there are many construction work on site, and fusion work between crosslinked polyethylene pipes also requires work on site. Therefore, it is necessary that anyone can realize the fusion of the crosslinked polyethylene pipes easily, surely and accurately without requiring skill.

Patent Documents 1 to 5 below disclose an invention relating to fusion between crosslinked polyethylene pipes and an invention relating to a fusion splicing method for thermoplastic members such as polyethylene.
JP-A-11-002383 Japanese Patent Laid-Open No. 10-281382 JP 07-276502 A Japanese Patent Laid-Open No. 06-074386 Japanese Patent Laid-Open No. 05-340496

  The problems to be solved by the present invention are that the resources of the crosslinked polyethylene pipe are not effectively used in the connection between the crosslinked polyethylene pipes, and that skill is required in the construction on site. Accordingly, an object of the present invention is to provide a cross-linked polyethylene pipe connection structure that enables the fusion of cross-linked polyethylene pipes with certainty and accuracy while making effective use of resources and facilitating on-site construction. It is to provide.

  The cross-linked polyethylene pipe connection structure according to the present invention is a cross-linked polyethylene pipe connection structure in which the first cross-linked polyethylene pipe and the second cross-linked polyethylene pipe are connected using an adhesive member, and the second cross-linked polyethylene pipe is connected to the cross-linked polyethylene pipe. On the connection end side of the tube with the first cross-linked polyethylene pipe, a concave region capable of receiving the connection end side of the first cross-linked polyethylene pipe is provided on the inner peripheral surface of the second cross-linked polyethylene pipe. A heating element capable of generating heat by electromagnetic induction is provided in the region, and the adhesive member is configured to insert the connection end of the first crosslinked polyethylene tube into the recessed region of the second crosslinked polyethylene tube. 1 It has a cap structure attached so that the connection end side of a crosslinked polyethylene pipe may be covered.

  Moreover, as a preferable form, the cap structure is provided on a cylindrical portion that covers an outer peripheral surface on a connection end side of the first cross-linked polyethylene tube, and on one end side of the cylindrical portion, and is connected to the first cross-linked polyethylene tube. And an annular flange portion extending toward the inner peripheral side so as not to exceed the thickness of the first cross-linked polyethylene pipe.

  Furthermore, as a preferred embodiment, the axial length of the cylindrical portion is the second length when the cylindrical portion is attached to the connection end of the first cross-linked polyethylene pipe and inserted into the recessed area of the second cross-linked polyethylene pipe. The length is set so as not to be exposed from the end of the cross-linked polyethylene pipe.

  Furthermore, as a preferable form, the adhesive member is made of polyethylene.

  Furthermore, as a preferred embodiment, the heating element is provided in a spiral shape, and a spiral recess groove is provided in the recess area to accommodate the heating element.

  In the adhesive member based on this invention, it is an adhesive member used for the connection of a 1st crosslinked polyethylene pipe and a 2nd crosslinked polyethylene pipe, Comprising: The said adhesive member connects the connection end of the said 1st crosslinked polyethylene pipe to the said 1st A cap structure that is attached so as to cover a connection end side of the first crosslinked polyethylene pipe so as to be inserted into a recessed area provided in the two crosslinked polyethylene pipe, and the cap structure is configured to include the first crosslinked polyethylene pipe. A cylindrical portion that covers the outer peripheral surface of the connecting end side of the first cylindrical cross-linked polyethylene tube, and a cylindrical portion that is provided on one end side of the cylindrical cylindrical portion so as not to exceed the thickness of the first cross-linked polyethylene tube And an annular flange portion extending to the inner peripheral side.

  According to the connection structure of the cross-linked polyethylene pipe based on the present invention, a cap structure that is attached so as to cover this region is adopted on the connection end side of the first cross-linked polyethylene pipe, which is a place requiring fusion. By using an adhesive member (for example, polyethylene), it is possible to avoid the use of the adhesive member in a portion that is not necessary and to effectively use resources. In addition, since a cap structure is used and a fusion structure based on an electromagnetic induction method is used, the end portion is cut on site to adjust the length of the first crosslinked polyethylene pipe, and the cut end surface is not good. Even if it becomes a regular shape (for example, in an inclined state), it is possible to make the end flat by attaching an adhesive member, which is easy and reliable without requiring skill. In addition, it is possible to fuse the cross-linked polyethylene pipes together.

  Moreover, the structure which has an annular flange part extended to an inner peripheral side is employ | adopted as a cap structure so that it may not exceed the thickness of a 1st bridge | crosslinking polyethylene pipe | tube. During heating, the flange portion of the adhesive member expands in volume toward the inside. However, by providing in advance so as not to exceed the thickness of the first crosslinked polyethylene tube, the flange portion does not protrude from the inner wall surface of the first crosslinked polyethylene tube even after expansion. As a result, no projecting portion directed inwardly from the inner wall surface of the tube is formed at the connection portion between the tubes, and thus does not hinder the flow of fluid flowing in the tube.

  Moreover, as a cap structure, the axial length of the cylindrical part is attached to the connection end of the first cross-linked polyethylene pipe, and is inserted into the recessed area of the second cross-linked polyethylene pipe. The length is set so as not to be exposed from the part. At the time of heating, the cylindrical portion of the adhesive member expands outwardly. Thereby, an adhesive member will be exposed from the clearance gap of the connection part of a 1st crosslinked polyethylene pipe and a 2nd crosslinked polyethylene pipe after heat fusion. As a result, it becomes possible to visually confirm the heat fusion between the first crosslinked polyethylene tube and the second crosslinked polyethylene tube.

  Hereinafter, a cross-linked polyethylene pipe connection structure 1A according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an exploded perspective view for showing a cross-linked polyethylene pipe connection structure 1A in the present embodiment, and FIG. 2 is an axial cross-sectional view showing the structure of the second cross-linked polyethylene pipe on the connection end side. FIG. 3 is an axial sectional view showing the structure of the adhesive member, and FIG. 4 is an axial sectional view before fusion in a state where the first crosslinked polyethylene pipe and the second crosslinked polyethylene pipe are connected. FIG. 5 is a sectional view in the axial direction after fusion in a state where the first crosslinked polyethylene pipe and the second crosslinked polyethylene pipe are connected, and FIG. 6 shows the first crosslinked polyethylene pipe and the second crosslinked polyethylene pipe. It is an axial sectional view showing a positional relationship with an electromagnetic induction device in a state where a crosslinked polyethylene pipe is connected.

<Connection structure 1A>
First, referring to FIG. 1, an outline of a cross-linked polyethylene pipe connection structure 1 </ b> A in the present embodiment will be described. A first cross-linked polyethylene pipe 100 and a second cross-linked polyethylene pipe 300 are prepared, and a cap-shaped adhesive member 200 is attached to a connection end side of the first cross-linked polyethylene pipe 100 with the second cross-linked polyethylene pipe 300. The inner diameter of the first crosslinked polyethylene tube 100 and the inner diameter of the second crosslinked polyethylene tube 300 are provided at the same inner diameter (D6, see FIG. 2). For example, based on JIS standard (Japanese Industrial Standard), nominal diameters 10A, 13A, 20A and the like can be mentioned.

<Recessed region 302>
As shown in FIG. 2, the second cross-linked polyethylene pipe 300 is connected to the first cross-linked polyethylene pipe 100 to receive the first cross-linked polyethylene pipe 100 to which the adhesive member 200 is attached. A recessed region 302 is formed that is thinner than the thickness. An inner diameter D5 of the recessed area 302 is provided with substantially the same dimension as the outer diameter (D2, see FIG. 3) of the adhesive member 200. Further, a contact wall 304 is formed between the recessed region 302 and the pipe line 305 in order to accurately perform positioning when the first crosslinked polyethylene pipe 100 and the adhesive member 200 are inserted into the recessed region 302. .

  Further, in the recessed area 302, a heating element 400 capable of generating heat by electromagnetic induction using an electromagnetic induction device provided outside is provided. In the present embodiment, the heating element 400 is provided in a spiral shape, and the recess region 302 is provided with a spiral recess groove 303 (depth D6) in order to accommodate the heating element 400. It has been. Thus, by rotating the heating element 400, it is possible to easily attach to the recessed groove 303 provided in the recessed region 302. In addition, from the viewpoint of ease of mounting and heat generation efficiency, the spiral-shaped heating element 400 is used, but a heating element such as a ring shape or a plate shape can also be used. As the material of the heating element 400, any material can be used as long as it can generate heat by electromagnetic induction. Examples of general materials include SUS430 and SUS304. Further, as described above, not only when the heating element is attached to the recessed area 302 later, it is also possible to adopt integral molding in which the heating element is embedded.

<Adhesive member 200>
Next, the structure of the adhesive member 200 in this Embodiment is demonstrated. The adhesive member 200 is made of polyethylene. In this embodiment, polyethylene is used as the optimum material from the viewpoint of heat fusion between the crosslinked polyethylene tubes, but other materials than polyethylene may be used as long as they have other equivalent properties. It is also possible to apply to the adhesive member 200.

  As shown in FIGS. 1 and 3, the cap shape of the adhesive member 200 is provided on the cylindrical portion 201 that covers the outer peripheral surface on the connection end side of the first cross-linked polyethylene pipe 100 and on one end side of the cylindrical portion 201. And an annular flange portion 202 that extends to the inner peripheral side so as not to exceed the thickness (t2, see FIG. 1) of the first crosslinked polyethylene tube 100 when attached to the first crosslinked polyethylene tube 100, and has an opening diameter. The opening of (D4) is defined. Therefore, the width (D3) of the flange portion 202 is dimensioned so as to satisfy the relationship of t1 <D3 <[t1 + t2]. In addition, t1 has shown the thickness (refer FIG. 3) of the cylindrical part 201. FIG.

  Thus, by setting the width (D3) of the flange portion 202, as shown in FIG. 4, the adhesive member 200 is attached to the first cross-linked polyethylene pipe 100, and the first cross-linked polyethylene pipe 100 is connected to the second cross-linked polyethylene. In a state of being inserted into the recessed region 302 of the tube 300, a recessed portion (gap) having a dimension S1 is formed between the inner peripheral end surface of the flange portion 202 and the inner peripheral surfaces of the first crosslinked polyethylene tube 100 and the second crosslinked polyethylene tube 300. Can be formed.

  Further, as shown in FIG. 4, the axial length L <b> 1 of the cylindrical portion 201 is such that the adhesive member 200 is attached to the first cross-linked polyethylene pipe 100, and the first cross-linked polyethylene pipe 100 is a concave portion of the second cross-linked polyethylene pipe 300. The length is set so as not to be exposed from the end of the second cross-linked polyethylene pipe 300 in the state of being inserted into the region 302. Thereby, as shown in FIG. 4, a recess (gap) having a dimension S <b> 2 can be formed between the end surface of the tubular portion 201 and the end surface of the second cross-linked polyethylene pipe 300.

<Fusion process>
Next, with reference to FIG. 4 and FIG. 6, the fusion | fusion process of the 1st crosslinked polyethylene pipe 100 and the 2nd crosslinked polyethylene pipe 300 is demonstrated. First, as shown in FIG. 4, the first crosslinked polyethylene tube 100 is inserted into the recessed region 302 of the second crosslinked polyethylene tube 300 with the adhesive member 200 attached to the first crosslinked polyethylene tube 100. In this state, as described above, a recess (gap) having a dimension S1 is formed between the inner peripheral end surface of the flange portion 202 and the inner peripheral surfaces of the first crosslinked polyethylene pipe 100 and the second crosslinked polyethylene pipe 300. The In addition, a recess (gap) having a dimension S <b> 2 is formed between the end surface of the tubular portion 201 and the end surface of the second crosslinked polyethylene pipe 300.

  Next, as shown in FIG. 6, a ring-shaped electromagnetic induction device 500 is disposed so as to contact the outer peripheral surface of the second crosslinked polyethylene pipe 300 so as to surround the recessed area 302 of the second crosslinked polyethylene pipe 300. To do. Thereafter, the electromagnetic induction device 500 is operated to cause the heating element 400 to generate heat. As a result, the adhesive member 200 is melted, and as shown in FIG. 5, with the adhesive member 200 interposed, the outer surface of the first crosslinked polyethylene tube 100 and the inner surface of the second crosslinked polyethylene tube 300, and the first crosslinked polyethylene. The distal end surface of the tube 100 and the abutting wall 304 of the second crosslinked polyethylene tube 300 are fusion-connected.

  An example of the conditions when the nominal diameter of the first crosslinked polyethylene pipe 100 and the second crosslinked polyethylene pipe 300 is 13A is as follows.

Shape of heating element 400: Spiral Wire diameter of heating element 400: about 1.2 mm
Material of heating element 400... SUS430 or SUS304
Electromagnetic induction device Frequency: 35 kHz
Time ... 2 to 4 minutes Heating temperature ... 180 ° C to 230 ° C
(Action / Effect)
Thus, according to the connection structure of the first crosslinked polyethylene tube 100 and the second crosslinked polyethylene tube 300 using the adhesive member 200 in the present embodiment, the first crosslinked polyethylene tube that is a portion requiring fusion. By using the adhesive member 200 that employs a cap structure that is mounted to cover this region on the connection end side of the 100, the use of the adhesive member 200 in an unnecessary place is avoided, and effective use of resources is achieved. Is possible. Further, even when the end portion is cut to adjust the length of the first cross-linked polyethylene pipe 100 at the site, and the cut end surface has an irregular shape (for example, a slightly inclined state), the adhesive member 200 is used. By mounting the end portions, the end portions can be made flat, and the cross-linked polyethylene tubes can be fused easily and reliably without requiring skill.

  Further, during heating, the flange portion 202 of the adhesive member 200 expands in volume (in the direction of arrow B). However, since the width D3 of the flange portion 202 is provided in advance so as not to exceed the thickness t2 of the first cross-linked polyethylene pipe 100, the flange portion 202 remains from the inner wall surface of the first cross-linked polyethylene pipe 100 even after expansion. It does not protrude. As a result, no projecting portion directed inward from the inner wall surface of the tube is formed at the connection portion between the tubes, so that the flow of fluid flowing in the tube is not hindered.

  In addition, the axial length L1 of the tubular portion 201 of the adhesive member 200 is the second length in the state where the tubular portion 201 is attached to the connection end of the first cross-linked polyethylene pipe 100 and inserted into the recessed region 302 of the second cross-linked polyethylene pipe 300. Since the length is set so as not to be exposed from the end of the cross-linked polyethylene pipe 300, the cylindrical portion 201 of the adhesive member 200 expands in volume toward the outside (A in the figure) during heating. As a result, the adhesive member 200 is exposed from the gap in the connecting portion between the first crosslinked polyethylene tube 100 and the second crosslinked polyethylene tube 300 after heat fusion. As a result, it becomes possible to visually confirm the heat fusion between the first crosslinked polyethylene pipe 100 and the second crosslinked polyethylene pipe 200. In particular, when the adhesive member 200 is colored in a color different from that of the first cross-linked polyethylene pipe 100 and the second cross-linked polyethylene pipe 200, the heat-sealed state can be easily visually confirmed.

  In the present embodiment, the case where the recessed region 302 is provided at the end of the second crosslinked polyethylene pipe 200 has been described. However, the connection structure of the present invention may be applied to pipe joints such as elbows and T-shaped pipes. Is possible.

  Accordingly, the above-described embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiments, but is defined based on the description of the claims. Further, all modifications within the meaning and scope equivalent to the scope of the claims are included.

It is a disassembled perspective view for showing a cross-linked polyethylene pipe connection structure 1A in the present embodiment. It is an axial sectional view showing the structure of the connecting end portion side of the second crosslinked polyethylene pipe in the present embodiment. It is an axial sectional view showing the structure of the adhesive member in the present embodiment. It is an axial direction sectional view before fusion in the state where the 1st crosslinked polyethylene pipe and the 2nd crosslinked polyethylene pipe in this embodiment were connected. It is an axial direction sectional view after fusion in the state where the 1st crosslinked polyethylene pipe and the 2nd crosslinked polyethylene pipe were connected in this embodiment. It is an axial direction sectional view showing the positional relationship with an electromagnetic induction device in the state where the 1st crosslinked polyethylene pipe and the 2nd crosslinked polyethylene pipe were connected in this embodiment.

Explanation of symbols

  1A connection structure, 100 first cross-linked polyethylene pipe, 200 adhesive member, 201 cylindrical part, 202 flange part, 302 concave part, 300 second cross-linked polyethylene pipe, 303 concave groove, 304 abutting wall, 305 pipe, 400 heat generation Body, 500 electromagnetic induction device.

Claims (6)

A connection structure of a crosslinked polyethylene pipe, wherein the first crosslinked polyethylene pipe (100) and the second crosslinked polyethylene pipe (300) are connected using an adhesive member,
On the connection end side of the second crosslinked polyethylene pipe (300) with the first crosslinked polyethylene pipe (100), the first crosslinked polyethylene pipe (100) is formed on the inner peripheral surface of the second crosslinked polyethylene pipe (300). ) Is provided with a recessed area (302) capable of receiving the connection end side of
The concave region (302) is provided with a heating element (400) capable of generating heat by electromagnetic induction,
The adhesive member is
The connection end side of the first cross-linked polyethylene pipe (100) is arranged so that the connection end of the first cross-linked polyethylene pipe (100) can be inserted into the recessed area (302) of the second cross-linked polyethylene pipe (300). Having a cap structure mounted to cover,
Cross-linked polyethylene pipe connection structure. The cap structure is
A cylindrical part (201) covering the outer peripheral surface of the first crosslinked polyethylene pipe (100) on the connection end side;
Provided on one end side of the tubular part (201), and extends to the inner peripheral side so as not to exceed the thickness of the first crosslinked polyethylene pipe (100) when attached to the first crosslinked polyethylene pipe (100). An annular flange (202);
The connection structure of the crosslinked polyethylene pipe | tube of Claim 1 which has these.   An axial length (L1) of the cylindrical part (201) is attached to a connection end of the first crosslinked polyethylene pipe (100) and is formed in the recessed area (302) of the second crosslinked polyethylene pipe (300). The connection structure of the crosslinked polyethylene pipe | tube of Claim 2 set to the length which is not exposed from the edge part of the said 2nd crosslinked polyethylene pipe | tube (300) in the inserted state.   The cross-linked polyethylene pipe connection structure according to claim 1, wherein the adhesive member is made of polyethylene. The heating element (400) is provided in a spiral shape,
5. The cross-linked polyethylene pipe connection structure according to claim 1, wherein a spiral recess groove (303) is provided in the recess area (302) to accommodate the heating element (400). An adhesive member used for connecting the first crosslinked polyethylene pipe (100) and the second crosslinked polyethylene pipe (300),
The adhesive member is
Connection end side of the first cross-linked polyethylene pipe (100) so that the connection end of the first cross-linked polyethylene pipe (100) can be inserted into a recessed area (302) provided in the second cross-linked polyethylene pipe (300). Having a cap structure that is mounted to cover
This cap structure
A cylindrical part (201) covering the outer peripheral surface of the first crosslinked polyethylene pipe (100) on the connection end side;
Provided on one end side of the tubular part (201), and extends to the inner peripheral side so as not to exceed the thickness of the first crosslinked polyethylene pipe (100) when attached to the first crosslinked polyethylene pipe (100). An annular flange (202);
An adhesive member.

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